CHAP. II. STAMENS. 149 



nective. In many of the cases of excessive divergence of the 

 cells the line of dehiscence of the anther is changed from lon- 

 gitudinal to vertical (Plate III. fig. 20. 17.), and has actually 

 been supposed to be really transverse ; an error which in most 

 cases has arisen from not understanding the real structure of 

 the anther. Some anthers, however, no doubt have cells that 

 burst transversely, as Lemna, Alchemilla arvensis, Securi- 

 nega, &c. (See Plate III. fig. 12. 16. 30.) 



All anthers are not two-celled, their internal structure 

 being subject to several modifications. It sometimes happens 

 that the septum, instead of being very obscurely formed, pro- 

 jects forward into the cavity of the anther, till it meets the 

 inflexed lips of the fissure : in such a case the anther is spu- 

 riously four-celled, as in Tetratheca. In Epacris the two 

 parallel cells become confluent into one, and the anther is 

 therefore one-celled. In Maranta and Canna only one cell 

 is produced, the other being entirely suppressed. In most 

 Amarantaceae, and some other plants, the anther seems to be 

 absolutely one-celled. (Plate IV. fig. 8.) 



Other deviations from the normal form of anther occur, 

 which are less easy to reconcile with the idea of a two-celled 

 t}^e. In some Laurineae the anther is divided into four cells, 

 one placed above the other in pairs ; in ^giceras it consists 

 of numerous little cavities ; and in the singular genus Rafflesia 

 the interior is separated into many cellules of irregular figure 

 and position, described by Brown as " somewhat concentrical, 

 longitudinal, the exterior ones becoming connivent towards 

 the apex, sometimes confluent, and occasionally interrupted 

 by transverse partitions." In these instances the septa may 

 be understood to arise from portions of the cellular tissue of 

 the anther remaining unconverted into pollen. 



With regard to the deviation from the usual mode of de- 

 hiscence. Brown observes {Linn. Trans, xiii. 214.), " that 

 they are numerous : in some cases consisting either in the 

 aperture being confined to a definite portion, — generally the 

 upper extremity of the longitudinal furrow, — as in Dillenia 

 and Solanum ; in the apex of each theca being produced 

 beyond the receptacle of the pollen into a tube opening at 



L 3 



